Assam Journal of Anaesthesiology

This review explores the mechanisms of unconsciousness from an anaesthesiology perspective, defining consciousness through clinical characteristics such as wakefulness and awareness. General anaesthesia induces a unique, reversible state distinct from natural sleep, where unresponsiveness does not necessarily equate to unconsciousness. This review article examines the Neural Correlates of Consciousness (NCC) and neurophysiological mechanisms, detailing how anaesthetics disrupt information integration across cortical and subcortical networks. Furthermore, it discusses neurochemical mechanisms, specifically the modulation of neurotransmitters like GABA and NMDA, and ion channels, which underpin the loss of consciousness.

Neuromuscular blocking agents (NMBA) are an integral part of modern anaesthesia, used in both operation theatres and intensive care units, facilitating tracheal intubation, optimizing surgical conditions and aiding mechanical ventilation. The advent of newer generation NMBAs including Rocuronium, emerging ultra-short acting Gantacurium and CW002 promise rapid onset with spontaneous recovery and minimal cardiovascular effects. Novel reversal drugs like Calabadion and cysteine-based compounds are under development, aiming for broader and faster antagonism of neuromuscular block.

This overview elucidates the physical principles essential to anaesthesia breathing systems, connecting theory to clinical safety. It explores fundamental gas laws, including Boyle's, Dalton's, and Henry's, explaining their role in gas uptake and delivery. The text analyzes flow dynamics, resistance, and compliance, illustrating their impact on the work of breathing. Furthermore, it details the classification and mechanics of Mapleson circuits (A–F) and circle systems, addressing rebreathing, dead space, and fresh gas flow requirements.

Fascial plane blocks (FPBs) have witnessed a surge in clinical practice as integral components of opioid-sparing multimodal analgesia. Unlike traditional techniques, FPBs deposit local anaesthetics into inter-fascial spaces, relying on complex mechanisms such as bulk flow, diffusion, and vascular uptake to modulate pain. This review elucidates the anatomical basis and pharmacological behaviour of FPBs, underscoring their value when neuraxial blocks are contraindicated.

Antibiotic stewardship in the Intensive Care Unit (ICU) is a pivotal challenge for intensivists, particularly within India's semi-open ICU systems. Inappropriate antibiotic use accelerates drug resistance, increases mortality, and raises treatment costs. This document summarizes core elements for successful stewardship programs, which rely on strong leadership, accountability, and multidisciplinary collaboration. Essential strategies involve antibiotic "time outs" after 48 hours, reassessment, prospective audits, and pharmacy-driven interventions.

Pain is a complex, multidimensional protective mechanism involving sensory, emotional, and cognitive components, rather than a simple stimulus-response phenomenon. This overview delineates the ascending pain pathway, spanning transduction by nociceptors and transmission via afferent fibers to conscious perception in the brain. It further explores the nervous system's capacity to modulate signals through peripheral sensitization, spinal mechanisms like the Gate Control Theory, and descending inhibitory pathways involving endogenous opioids.